I recently read an article about extrude honing. I'm familiar with what the process dose. In the article they were able to improve the air flow of an intake manifold by 30%. That is a pretty substantial increase in air flow. I looked into it some more, and the process is pretty interesting. I think it is much more accurate that plain old porting. I'm aware that there are some on this site that have had the heads ported and polished on their car. Has any one done this with the intake plenum. The reason I ask is because, I have the plenum off of my 348 right now. I cleaned out the inside of the plenum, and man was it nasty! I also removed the throttle bodies and cleaned those too. I looked at the thickness of the plenum, and there seems to be some material that can be removed. Since it is off I figure I may get it extrude honed, to increase the flow of the intake, in an attemp to get some more power and torque. It will reduce were the two flutes meet, turning into the one runner, that goes to the intake port of the head. The other area the looks like it will affect, is were the injectors are located. Do the injectors have to sit back, or can they come closer, or even protrude a little bit inside the runner. So I would like to know what those of you that know, think, before I decide on what I'm gonna do. Currently I'm leaning towards doing it, because I would like to get some more ooomf out of the engine. What are the pro's and con's of getting the intake extrude honed?